DIY-Central.com - Go Create something! - PCB Design, Electronics

I designed a new PSU for people who'd like to rack those Yamaha PM1000 channel strips.

The Yamaha PM1000 are usually called Japanese "Neves" because of a similar approach in design. Just like the Neves, this is all discrete transistor and uses an input transformer and output transformer.

The EQ section is especially sweet because there is not a single IC on this preamp. The EQ section uses inductors and capacitors... totally analog manipulation and shaping of your frequency. (circa 1974)

I've tested them on drums and vocals and they really make the sound FAT. The EQ section shapes your sound anywhere from slight barely noticeable to extreme gain/reduction. Bass frequencies are solid. Of course, being an analog EQ, it is not as precise in shaping the sound as IC chip Equalizers. But the curve is smoother I would think.

So if you're racking a PM1000 strip you bought from eBay, this PSU will be perfect for you. Output is +44VDC and +48VDC for the Phantom Power.

I'm having prototypes built. If you're interested, email me.

Screenshot:

PCB Rev.2.00



The new PCB designs will be smaller and double-sided measuring 2.25" x 2.25" 

I don't have this mass-manufactured, so I'm selling it at a low price just to recover some of my costs.  $20 each.  Email me first  before ordering. Thanks.

This is a continuation of my Sony Racking Job. Click here for previous article.
http://diy-central.com/DIYRackingSonyMXPPreampsAndEQModules.aspx

Things are progressing nicely. Some photos.

Finally cut the hole for the EQ section... took about 2+ hours... it's a pain doing this. And I have to be careful not to make the square holes too big because the tolerances are very tight.

Some closeup photos of the Preamp and EQ module.

Things are busy at DIY Central... I also had PCBs manufactured for my PRE-1048 preamp (link coming soon). This time, I used a company based in Malaysia.  I got the PCBs today too, same day as my PSU PCBs.

Well, I'm a bit disappointed at the quality. Let's just say it's nowhere near the quality of the other PCBs I got manufactured here in the US. (See photo of article below this.)

There's also no silkscreen (but I knew that before I placed the order).... it's also more expensive than the US manufacturer if you divide the total price by the number of PCBs you get.

To their credit, they got the PCBs manufactured correctly. :)

This is a continuation from this article.
http://www.diy-central.com/DIYSplitPowerSupplyWith48VPhantomPower.aspx

Well, I received the PCBs today but it seems there was a manufacturing error. Everything is flipped/mirrored... Here's how the top layer looks like... the bottom layer is also flipped/mirrored.

BUMMER!

I sent this picture to the manufacturer along with what the Eagle board is supposed to look like. I emailed them... and within a couple of hours, I got a call from them on the phone apologizing for the mistake and they found out where in their process they had the mistake... they're going to remanufacture my boards and resend them to me at no charge!  Talk about great service!  The quality of the boards and it's workmanship do look very nice too, and their prices are great.

This is my first order from them, and even if they did screwed this up, I think I'll use them in the future. I like how they handled the problem very well and took steps to correct it.

I'll keep you guys updated about the progress.

Just some preliminary pictures... I'll post the writeup later.

This is a Valley People Trans-Amp Mic Pre. No, this is not a discrete opamp like the 990 or API2520. This is a complete mic preamp in a "box."

The Trans-Samp have 9 pins at the bottom. I used some Mill-Max pins to socket them to the breadboard.

I decided to rack the few remaining Sony MXP preamp and EQ modules I have. This particular mic pre module is using a discrete opamp enclosed in some green colored epoxy or something.

I've already racked a previous Sony mic pre and EQ, so I want this 2nd unit to match the layout of the first one I did. The only difference is this particular project, the mic pre does not have the Jensen transformers, and instead is using some discrete opamp, and will be in a black 1u case.

Here are some preliminary pictures.



The Mic Pre and EQ module I'll be racking.



Preparing the 1u front panel for drilling holes.

Having a drill press makes the job so much easier than using a hand drill. Safety first... don't forget to use goggles. Freak accidents happen, like a drill bit breaking and flying into your eye! (good thing I had the goggles!) So no matter show "quick" a job it is, don't forget your safety glasses or goggles.

I decided to design my own PCB for a general split power supply with +48VDC phantom power. The one I'm currently using while compact in size doesn't leave any room for a heatsink. So I moved all TO-220 voltage regulators to the side so I'll be able to attach a big heatsink and keep those VR cool to the touch.

Here's the schematic and prototype PCB design. I'm having these PCBs fabricated, as a test prototype.

Schematic diagram. From this schematic, I created the PCB design and exported Gerber files.

Then using a third-party Gerber Viewer, I opened up the created Gerber files to double check my layout. So far, everything looks good.

You can buy this kit from PAIA, including the cool-retro case, complete with electronic parts, power supply, knobs, manuals. They even throw in the wires.  You have the option of using a desktop case with wooden sides, or mount it on a 2u rack panel.

The price I think is also pretty reasonable considering that some of these things sell in the several hundreds.

The kit includes a burned EPROM (containing the programming). The code is also available on their website.  And note, this is not just some analog synth that doesn't play with others... it has MIDI. It responds to note-on/off data, including pitch, velocy and gate. So you can hook it up and make it part of your MIDI studio.

Writeup from their website.

The FatMan has all of the features that give analog it's big bottom
and punch in a MIDI controlled package. The classic Voltage Controlled
normalization is brought up to date with a Velocity CV not available on
pre-MIDI synths. Pitch wheel modulation is supported and Pitch and
Velocity CVs and gate signal are provided on the front panel for
driving PAiA or other linear response synthesizer modules.

And all those knobs. They invite experimentation and invention in
ways that a single control with functions buried under layers of
obscure menus never can. Just a few hours with the FatMan will teach
you more about the nature of sound than you might ever learn otherwise.
It's as at home in the physics lab as on-stage.

 

Isn't this a thing of beauty? And for a few dollars, you can build your own analog synth, a'la Bob Moog! Link to Project

Write up from the website:

These are instructions from converting a Renuzit Air Freshner to a trumpet mute. Another guy extended the concept by installing a mic and small preamp inside the air freshner case and hooking up a headphone.  Pretty cool.

Now you can toot and make it smell fresh at the same time!

Link for the trumpet mute. Link for the trumpet mute with mic, preamp and headphones.

This is a repost of my SSL Build Thread. Thanks to Gyraf.dk for the schematic plans.

The compressor is a clone based from the SSL4044E desk (1985 era). The SSL mixbus is actually an integrated part of the desk's main quad fader and autofade system. Click here for schematics.

There's been some mods to the original schematics for use with THAT VCAs. This page contains adjustments to the resistor values.

I also did some mods on my unit. Mainly, adding transformers at the output. Originally, the unit uses opamps for balanced outs. I have some MCI 416 output trafos that I used for my SSL unit.

The PCB...